This invention relates to benzofuran and benzothiophene sulfonamides which are novel. The compounds of this invention and their agriculturally suitable salts, are useful as agricultural chemicals, e.g., plant growth regulants and herbicides.
Netherlands Pat. No. 121,788, published Sept. 15, 1966, discloses the preparation of compounds of the following Formula and their use as general or selective herbicides: ##STR1## wherein R.sub.1 and R.sub.2 may independently be alkyl of 1-4 carbon atoms; and
R.sub.3 and R.sub.4 may independently be hydrogen, chlorine or alkyl of 1-4 carbon atoms. PA0 R.sub.2 is hydrogen, 2-pyrimidinyl, pyridyl, amidino, acetyl or carbamoyl. PA0 R.sub.4 is hydrogen, fluorine, chlorine, bromine or methyl; PA0 R.sub.5 is hydrogen, fluorine, chlorine, bromine, methyl or methoxy; PA0 R.sub.7 is hydrogen, fluorine, chlorine, bromine, alkyl of 1-2 carbon atoms or alkoxy of 1-2 carbon atom; PA0 R.sub.8 is hydrogen, methyl, chlorine or bromine; PA0 R.sub.9 and R.sub.10 are independently hydrogen, methyl, chlorine or bromine; PA0 W and Q are independently oxygen or sulfur; PA0 n is 0, 1 or 2; PA0 X is hydrogen, chlorine, bromine, methyl, ethyl, alkoxy of 1-3 carbon atoms, trifluoromethyl, CH.sub.3 S-- or CH.sub.3 OCH.sub.2 --; and PA0 Z is methyl or methoxy; PA0 (a) when R.sub.5 is other than hydrogen, at least one of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 is other than hydrogen and at least two of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 must be hydrogen; PA0 (b) when R.sub.5 is hydrogen and all of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 are other than hydrogen, then all of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 must be either chlorine or methyl; and PA0 (c) when R.sub.3 and R.sub.7 are both hydrogen, at least one of R.sub.4, R.sub.5 or R.sub.6 must be hydrogen. PA0 R.sub.1 is H, Cl, CH.sub.3 or OCH.sub.3 ; PA0 R.sub.2 is H or C.sub.1 -C.sub.4 alkyl; PA0 R.sub.3 is H or CH.sub.3 ; PA0 R.sub.4 is H or CH.sub.3 ; PA0 N-[(4-bromo-6-methoxypyrimidin-2-yl)aminocarbonyl]-2,3-dihydrobenzo[b]thiop hene-7-sulfonamide, 1,1-dioxide, m.p. 238.degree.-240.degree. C.; and PA0 N-[(4-bromo-6-methoxypyrimidin-2-yl)aminocarbonyl]-2,3-dihydro-2-methylbenz o[b]thiophene-7-sulfonamide, 1,1dioxide, m.p. 225.degree.-227.degree. C.
U.S. Pat. No. 3,637,366 discloses compounds having the formula: ##STR2## wherein R.sub.1 is hydrogen or lower saturated aliphatic acyl and
The disclosed compounds are said to provide control of crabgrass, cress, endive, clover and Poa annua.
French Pat. No. 1,468,747 discloses the following para-substituted phenylsulfonamides as being useful as antidiabetic agents: ##STR3## wherein R=H, halogen, CF.sub.3 or alkyl.
Logemann et al., Chem. Ab., 53, 18052 g (1959), disclose a number of sulfonamides, including uracil derivatives and those having the formula: ##STR4## wherein R is butyl, phenyl or ##STR5## and R.sub.1 is hydrogen or methyl.
When tested for hypoglycemic effect in rats (oral doses of 25 mg/100 g), the compounds in which R is butyl and phenyl were most potent. The others were of low potency or inactive.
Wojciechowski, J. Acta. Polon. Pharm. 19, p. 121-5 (1962) [Chem. Ab., 59 1633 e] describes the synthesis of N-[(2,6-dimethoxypyrimidin-4-yl)aminocarbonyl]-4-methylbenzenesulfonamide: ##STR6##
U.S. Pat. No. 4,127,405 teaches compounds which are useful for controlling weeds in wheat having the formula ##STR7## wherein R is ##STR8## R.sub.1 is ##STR9## R.sub.3 and R.sub.6 are independently hydrogen, fluorine, chlorine, bromine, iodine, alkyl of 1-4 carbon atoms, alkoxy of 1-4 carbon atoms, nitro, trifluoromethyl, cyano, CH.sub.3 S(O).sub.n -- or CH.sub.3 CH.sub.2 S(O).sub.n ;
or their agriculturally suitable salts; provided that:
The presence of undesired vegetation causes substantial damage to useful crops, especially agricultural products that satisfy man's basic food and fiber needs, such as cotton, rice, corn, wheat, and the like. The current population explosion and concomitant world food and fiber shortage demand improvements in the efficiency of producing these crops. Prevention or minimizing the loss of a portion of such valuable crops by killing, or inhibiting the growth of undesired vegetation is one way of improving this efficiency. A wide variety of materials useful for killing, or inhibiting (controlling) the growth of undesired vegetation is available; such materials are commonly referred to as herbicides. The need still exists however, for more effective, selective herbicides.